﻿/* 
 * Copyright (c) 2011 Jeff Zhang
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of 
 * this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation the rights to use, 
 * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, 
 * and to permit persons to whom the Software is furnished to do so, 
 * subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included 
 * in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

using System;
using System.Collections.Generic;
using System.Text;

namespace Json {
    internal class CharBuffer {
        public int BUFFER_SIZE = 1024;
        private int _size;
        private char[] _buffer;
        private int _pointer = 0;

        public CharBuffer() : this(256) { }

        public CharBuffer(int bufferSize) {
            if (bufferSize < 1) {
                throw new ArgumentOutOfRangeException("bufferSize", "The buffer size must be larger than zero.");
            }

            _size = BUFFER_SIZE = bufferSize;
            _buffer = new char[BUFFER_SIZE];
        }

        public string GetString() {
            char[] buf = new char[_pointer];
            Array.Copy(_buffer, buf, buf.Length);

            return new string(buf);
        }

        public char Pop() {
            if (_pointer == 0)
                return BufferedCharReader.EOF;

            return _buffer[--_pointer];
        }

        public void Push(char chr) {
            if (_pointer == BUFFER_SIZE - 1) {
                _size += BUFFER_SIZE;
                char[] buf = new char[_size];
                Array.Copy(_buffer, buf, _buffer.Length);
                _buffer = buf;
            }

            _buffer.SetValue(chr, _pointer++);
        }
    }
}
